The present invention generally relates to insulation and more specifically to a foam composite insulation for aircraft.
Insulation is typically provided on the exterior and/or interior of aerospace systems, particularly between the outer bodies and the internal passenger compartments of aircraft fuselages. The insulation provides a number of functions including regulation of temperature, reduction of engine noise, reduction of noise from outside air turbulence, and protection of mechanical and structural components within the aerospace systems from moisture and temperature extremes that might tend to damage or corrode the components. All of these functions are enhanced by the close contact of insulation to fuselage surfaces including frames, stringers and skin, as well as close contacting fit to brackets and unrelated hardware that is fastened to the fuselage.
Until recently, fiberglass batting had been the preferred insulation for use within aircraft and other aerospace structures. Fiberglass has good thermal and structural properties, is fairly inexpensive, and has a long history of successful use in the aerospace industry.
Recently, foam insulation has been introduced for fuselage insulation. In fact, many companies use closed cell foam as a layer for fuselage insulation, while others use a polyimide type open cell foam. However, the use of foams is typically limited to where the foam layer is designed for interlocking fit. Interlocking fit designs are a problem because they are limited to fuselage designs that coincidentally have structural flanges that allow the insulation to be tucked (i.e. to be interlocked) behind the string flanges, or behind the intercostals, thereby creating the interlocking fit.
Closed cell foams are also desirable because they are relatively moisture resistant. However, thin closed cell foams also do not typically provide adequate noise absorption for use in aircraft fuselages. As such, the amount of closed cell foam that must be used adds to manufacturing costs in terms of raw material costs, installation costs, weight, and space constraints.
It is thus highly desirable to create a new acoustical and thermal insulation that is easy to use and install. It is also desirable that the insulation be cost effective in terms of fabrication, installation and life cycle. It is also desirable that the insulation be relatively water resistant.